A vehicle telematics system is typically a system installed in a vehicle that is capable of determining the location of the vehicle and communicating the vehicle's location to a remote location via a wireless communication link. Vehicle telematics systems are installed in a variety of applications including, but not limited to, fleet management, vehicle finance, vehicle maintenance, driver management, and/or fuel management.
A common configuration for a vehicle telematics system is illustrated in FIG. 1. The vehicle telematics system 10 includes a processor 12 that is configured to communicate with a radio transceiver 13 and a GPS receiver 14. The processor 12, the radio transceiver 13, and the GPS receiver 14 are typically powered by a power supply 15 that is connected via a line to the vehicle's battery. The vehicle telematics system can optionally include its own battery 16 to enable operation when the vehicle battery is removed and/or to prevent depletion of the vehicle battery. In many instances, the vehicle telematics system monitors the ignition line of the vehicle to determine the ignition state of the vehicle using an ignition input interface 17 that is connected to the vehicle ignition line. Monitoring the vehicle ignition state can be useful for reasons including, but not limited to, reporting vehicle ignition state and/or managing power consumption.
A common problem encountered during installation of devices in a motor vehicle that connect to the vehicle's electrical system is that the installer may inadvertently connect the ignition input interface 17 to a wire that is not the vehicle ignition line. U.S. Pat. No. 6,163,690, the disclosure of which is incorporated by reference herein in its entirety, notes the potential for the ignition sense line of a hands-free adapter for a mobile phone to be incorrectly connected to a line other than the ignition line due to installer error, which can result in the hands-free adaptor believing the ignition is always on and undesirably draining the vehicle's battery. U.S. Pat. No. 6,163,690 proposes a system that checks the correctness of the ignition sense line installation by monitoring the ignition sense line to determine whether the ignition line is switched off within a predetermined time period. In the event that the hands-free adaptor detects that the ignition line is always on, the hands-free adaptor provides an indication that it has been installed incorrectly.